The participation of 12,000 students in years eight to 11 across 237 schools provides the first truly national sample for a physical activity survey of young Australians since 1985.

Key findings:

One in four students are overweight or obese, with a significantly higher rate in low SES areas.

Eighty-five per cent of students don't engage in sufficient activity to provide a health benefit.

Low fruit and vegetable intake, with 76% not meeting the daily recommended intake of four vegetable servings daily and 59% not meeting the daily recommended intake of three servings of fruit daily.

One third drink four or more cups of soft drink, cordial or sports drink a week

More than half (51%) tried a new food or drink product in the past month they had seen advertised.

Cancer Council Australia CEO, Professor Ian Olver, said the findings confirmed what health experts had been saying for years, that poor nutrition and inadequate exercise were contributing to an unprecedented number of overweight and obese adolescents and a "chronic disease time bomb".

"If ever there was a wake-up call for Australians, this is it," Professor Olver said. "As obese kids move into adulthood the heightened risk of chronic diseases like cancer means previous gains in life expectancy may be reversed. We may see today's teenagers die at a younger age than their parents' generation for the first time in history"

National Heart Foundation of Australia CEO, Dr Lyn Roberts, said that all policy makers should be deeply disturbed by the findings.

"This piece of research confirms what we've feared for some time - that the high school students of today will grow up to be the heart attack victims of tomorrow," Dr Roberts said.

Chair of Cancer Council Australia's Nutrition and Physical Activity Committee, Kathy Chapman, said the report provided compelling evidence for the Australian Government to implement a comprehensive obesity strategy, as recommended by the National Preventative Health Taskforce.

"Overweight and obesity significantly increase cancer risk and unless we address the problem, common cancers such as bowel and breast cancer will surge," Ms Chapman said.

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